Relay circuit



Feb. 6, 1951 v. L. CARTMELL 2,540,098

RELAY CIRCUIT Filed Oct. 16, 1945- VERNON L. CART/WELL %Mm9 L A T'TOR/VE) Patented Feb. 6, 1951 UNITED STATES "PATENT @QE-FICE RELAY CIRCUIT Vernon L. cartmelL'Dayton, Ohio APDIi OatiOIIL-OQtQhBI 16, 1945, Serial No. 622,542

(Cl. IVE- 320) :(Gmntednnderthe actof -Marchj, 1883, as amended April 30, 1928; 370 O. G. 757) 5 Claims.

l The I invention describedherein may be manu- .fa'ctured and used. by. .orsfor the, Government for governmental purposesywithout the .p ayment. to

-- me pf any royalty. thereon.

' This invention relates to a circuit;f; or: doubling the number of :channels availab1e;from a radio receiver selector.

-' One of the objects -of the invention-is to pro- "Vide a channel doublingcircuit Which requires no alterations. to :the existing equipment and which amaintains the initialsefiiciency of the system.

Another object is to. provide a channel doubling *means which utilizes aninterrupter circuit for keying the fixed-frequency tones of the modu- .-':lator and which isnot critical asto; the speed and length of .durationof. thepulse.

J A.further;objeot' is to providesuch a channel doubling means which requires only two relays in eachchannel availableain the receiver selector and: which operatesindependently of adjacent channels.

"These androtherobjects and advant ages ofthe .1 invention, .will become apparent in the; specifica- .tion nd inthe accompanying drawing in which the single figure illustrates schematically atypi- .;-.cal circuit embodying. the; invention.

., .A radio receiver selector isprovided .with

:anantenna-H and-includes a givennumberrof filter circuits responsive todifierent frequencies, .oneof which is shownat l2. This filter is shown ;'as a self-resonantccoilvbut'may beanytype of x-selectivefilter. The signal passed by filter i2 is ,fed to a receiver relay including a coil [3 and contacts I4, one side of the contacts being grounded as shown.

:Tbechannel doubling circuit includes relays Y and 2| having corresponding resistors 16 and 22 in shunt and in series respectively. Contact, I] of -'relay I5 is grounded as shown and is-normally mopen with respectto contact la, which connects to one terminal of-relay 2|. Contact I9 is con- ;nected to contact 25 of relay 2! and is normally 0pen.with respect to contact 20,.the latter being connectedto conductor-.28 which is part of one of the circuits tobe-controlled. Contact 23 of relay 2! is connected to the relay as shown and is normally closed with contact 24 which connects to one side of relay. [5. ContactsZi and 25 connect to conductors 29 and..3fl, respectively,

Which'are the other terminals of the circuit to be controlled.

In a circuit of the general class. of that just -described thereceivedsignal in a given channel will ordinarily operate only a single circuit, in a .positive. manner.. In the present inventiona sig- H l a iven frequency maybe sent-either continuously or intermittently to. operate ,.:e ither 0 of tWoseparatecircui-ts in, a positive manner without requiring any change in;the receiver.

When a continuous tone is receiyed in the radio receiver select or-,.the relay itresigonsive toethe corresponding frequency is energized and contact A e is closed, completing the circuit to 'elay/iIKi-FA completed circuit between 28anddfi is-nowpresent due tothe; closing of 7 contacts l9 andand through closed contacts and 26 of.lrelay 2 I. Relay 21 will notbe energized, i ecauseg round .is applied to both ends otthe coil through cen- We 23 M 2 aliqlleoe a ii ipne i a through contact. I l and] 8 in relay l5 on the. other side.

I the circuit between and andfretu and opening of contacts 19 and nth entire circuit to normal; unop mta ThlS completes one cyclein the-operatic of one channel in the relay bumm r channelzin the radio receiver selector.

A second channelis nowfavailable using relays 15 and 2 by lgeying-thisisarne.channel in thefradio receiver selecton, 'Onrece iving the first. p'u1se r y I5 i a a n n rgizedby theTCioSi'n Id,the

grelay. ontacts pl 4. op ning; of. contacts] 4 momentarily atathelehd a: the first. pulse. re-

.,.resistor 22 and-through contacts fl], and. l

moves the ground frorn the coil of relay 21, causing it. to. energize .by a .flow. of..current.' lthrough iiilr lay. I 5.. Contacts. LT and 18 re mairiclos ed. beyond theend oisaid firstpulse, even though the fco'ntacts. I are opened, since .relay.,l5 is. given adelay characteristic bythe. resistor 1.6 which is connected ac1'oss its,. winding, causing the. rel 'i remain energized lover a time interval. at least :qeoual to the timehetween .the pulses ofthe pulsed H signal. On the second pulse andpulses thereafter relay 2! willnot.deenergize b'ecause the ground return between resistor. 2:2 and thecoil has been broken through contacts..23 and 2: l on:re1ay 2l. The continuance of ,pulseswillcause relay i 5, .to

remain energized by" del aying; ,the drop out time due to resistor l6. A ;qi,rcuit is thus, estab and maintained between 2 8 'an d 2 91b? cloSiCQ tacts I Sand 20 on relay, 5. and eontalct s ii i 21 ,on. relay 2 l.

v selector opens contacts M on the Qreceiv A n e oireeeiv d Pul es 1. .re iorsce y relay paus relay 5 9. e n r abreein ca als and i r suli iin de nereiia q...

said first relay means is deene lay 2| and opening the circuit between 28 and 29 due to opening of contacts is in relay l and contacts 25 and ill in rela 2 i. This completes one cycle in the operation oi the second channel in the relay box from the same first channel in the radio receiver selector. The keying of the modulator may be accomplished by means of a motor driven circuit breaker or relay operated circuit breaker. The speed and length of the pulse from the transmitter is not critical but must be fast enough so as to overlap the dropout time of relay H5 in the relay circuit. In practice, changes or? pulse s3 ed and input voltage to relays l5 and of approximately 25% do not affect the operation of the circuit.

While I have shown only a single embodiment of my invention various modifications are possible within the scope and extent of the appended claims.

I claim:

1. In a relay system adapted to operate in response to a continuous or pulsating signal for selectively closing either one of a pair of electric circuits, the combination compris'ag first relay means arranged to be energized in response to input signals, second relay means a first circuit controlled by said first relay for efiecting energization of said second relay when said first relay means is energized, first delay means associated nal, third relay means, a second circuit controlled I by said first and said second relay for efiecting initial energization of said third relay only when gized and said iced under opsecond relay means is still en eration of said first delay means, second delay means associated with said third relay means for preventing deenergization of said third relay for an interval at least as long as the intervals between pulses of the pulsating signal, and a double-throw switch arranged to be controlled by said third relay for completing one or the other of said circuits.

2. In a relay system adapted to operate in response to continuous or pulsating signals selectively to close either one of a pair of electrical circuits, the combination comprising a first relay means including a coil and a normally open first switch arranged to be closed in response to sig- ,nals of either polarity passing through said coil, said first switch havin one side grounded, a second rela means including a coil and a normally open second switch, said second switch providing a connection to ground and delay means for preventing deenergization of said second relay coil for an interval at l ast as long as the intervals between pulses of said pulsating signal, said second relay coil being connected to said first relay switch to prevent energization thereof except when said first relay switch is closed, a third relay including a coil and a normally closed switch and delay means for preventing deenergization of third relay coil for an interval at least as long as the intervals between pulses of said pulsating current, said third relay coil being connected through said third relay switch to the ungrounded side or" said first relay switch and to said second relay switch to prevent initial energization thereof except when said first relay switch is open and said second relay switch closed under the operation of said second relay delay means and to permit the continued energization thereof during said pulsating signal, and a double-throw switch arranged to be controlled by said third relay for completing one or the other of said two circuits.

3. An electrical system for controlling the operation of two circuits, one in response to a continuous signal and the other in response to a pulsating signal, comprising a first source of electrical energy for energizing purposes, a second source of continuous and pulsating signals, a first relay including a single-throw switch normally open having a grounded side and a coil connected to said first source, a second relay including a single-throw switch normally open having a ground connection when closed and a coil connected between said energizing source and the ungrounded side of said first relay switch to be energized only when said first relay switch is closed, first delay means associated with said second relay to delay deenergization thereof for a timeinterval at least as long as the intervals between pulses of said pulsating signal, a third relay including a single-throw switch normally closed and a coil connected to the ungrounded sides of said first and second relay switches and said energizing source to be initially energized only when said first relay switch is open and said second relay switch is closed under the influence of said first delay means, second delay means associated with said third relay to prevent deenergization thereof for an interval at least as long as the intervab between pulses of said pulsating signal, and a double-throw switch arranged to be controlled by the coil of said third relay for completing one or the other of said two circuits.

l. An electrical system to control two circuits, one in response to a continuous signal and the other in response to a pulsating signal, comprising a source of electrical energy for energizing purposes, a source of continuous and pulsating signals, a first relay including a coil connected to said signal source and a first normally open single-pole, single-throw switch having a grounded side and connected to said energizing source, a second relay including a second normally open single-pole, single-throw switch and a coil connected between the ungrounded side of said first relay switch and said energizing source to be energized only when said first relay switch is closed, a first delay resistor connected to said second relay coil to delay the deenerglzation thereof for a time interval at least as long as the intervals between pulses of said pulsating signal, a third relay including a third normally-closed, singlepole, single-throw switch and a coil connected between said second relay switch and said ohergizing source, said third relay switch being connected between said third relay coil and said first relay switch to prevent energization of said third relay coil except when said first relay switch is open and said second relay switch is closed under operation of said first delay resistor, a second delay resistor connected to said third relay coil to prevent deenergization thereof at least as long as the intervals between pulses of said pulsating signal, an additional normally open, single-pole, single-throw switch arranged to be controlled by said second relay coil for Keeping both of said two circuits open except when a signal is received, and a single-pole, double-throw switch arranged to be controlled by said third relay coil for completing one or the other of said two circuits.

5. An electrical system to control two circuits, one in response to a continuous signal and the other in response to a pulsating signal, comprising a source of electrical energy for energizing purposes, a source of continuous or pulsating signals, a first relay including a coil connected to said signal source and a first normally-open switch connected to said energizing source and having a grounded side, a second relay including a coil connected between the ungrounded side of said first relay switch and said energizing source to be energized only when signals from said signal source close said first relay switch, first delay means associated with said second relay to delay the deenergization thereof for a time interval at least as long as the intervals between pulses of said pulsating signal, a third relay including a coil connected on one side to said energizing source, a second normally-open switch for providing a ground connection arranged to be controlled by said second relay and connected in circuit with said third relay coil and said energizing source, a normally-closed switch arranged to be energized by said third relay coil and connected between said one side of said third relay coil and the ungrounded side of said first relay switch to prevent energization of said third re- 6 lay when said first relay switch is closed, said third relay being energized when said first relay switch is opened and said second relay switch is still closed under operation of said first delay means, second delay means associated with said third relay to prevent deenergization thereof for an interval at least as long as the intervals between pulses of said pulsating signal and a doublethrow switch arranged to be controlled by the coil of said third relay for completing one or the other of said two circuits.

VERNON L. CARTMELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,090,912 Hailes Aug. 24, 1937 2,098,040 Hoppe Nov. 2, 1937 2,141,803 Thompson Dec. 27, 1938 2,277,579 Burger Mar. 24, 1942 2,293,932 Cooper Aug. 25, 1942 

